Coupling device for scaffoldings

ABSTRACT

A coupling device including a first tightening part and a second tightening part. The first tightening part includes a tightening surface and is moveable about a pivot axis. The second tightening part is also moveable about the pivot axis. The first tightening part and the second tightening part are translatable between a release position and a lock position, such that after said first tightening part is moveable about the pivot axis and into the locked position, the second tightening part is moveable about the pivot axis into said lock position.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a device for coupling scaffoldingelements to uprights in a scaffold according to the preamble of appendedclaim 1.

PRIOR ART

By for example SE-B-7908679-9, a coupling device is previously knownwith a locking device in the form of two tightening parts, one of itwhich consists of a locking wedge. The handling of the two tighteningparts needs to be done in several steps since the locking device doesnot have a stable release position.

SUMMARY OF THE INVENTION

The purpose of the present invention is thus to arrive at a couplingdevice with a locking device, which can, in a simple manner, be switchedbetween a release position and a locking position. The said purpose isobtained by means of a device-according to the present invention, thecharacteristics of which will become apparent by appended claim 1.

DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail in the following by meansof some embodiments with reference to the appended drawings.

FIG. 1 shows an example of a simple scaffolding at which the presentinvention can be applied.

FIG. 2 is a side view of a coupling device according to the invention inthe release position,

FIG. 3 is a side view of the device according to FIG. 2 with the devicein the locking position,

FIGS. 4 and 5 show views which correspond to FIG. 1 and 2 but withhidden lines added,

FIG. 6 is a view of the device from below,

FIGS. 7 and 8 are partial cross-sections of the device in the lockedposition from either side,

FIGS. 9 and 10 are a view of the device in the release position fromeither side while

FIG. 11 is a front view of a part of the device with a gripping part ofthe device not shown for the sake of clarity.

PREFERRED EMBODIMENT

FIG. 1 shows an example of a scaffolding 1, which is equipped withcoupling devices 2 which can be of the type provided by the invention.The scaffolding consists of a number of uprights 3, which at their lowerend rests on a surface which can be the ground, a sidewalk, a floor orthe like. In the scaffolding is comprised, except for the uprights,another type of scaffolding elements, a number of horizontal scaffoldingelements 4, 5 which, for example, by means of the coupling devices 2according to the invention are coupled to the uprights. Since thehorizontal scaffolding elements at their both ends are coupled to theuprights, the horizontal scaffolding elements are supported by means ofthe coupling. The coupling device according to the invention is anextremely rigid coupling, which means that the scaffolding can standalone, but in a traditional application when positioned at a building,it is usually fastened to the building for safety reasons. Thetraditional scaffolding has as its object to support not shown buildingplatforms, which usually rest between the horizontal coupling elements5, but the scaffolding can have a number of various applications andfunctions, such as, for example, forming a stage, scaffolding at variousevents, to support weather shelters for people, vehicles, boats,buildings, to support signs or to form a so-called brace to support castconstructions during building. As will become evident from FIG. 1, theuprights 3 exhibit a number of gripping parts 6 arranged over the lengthof the uprights at different levels and being part of the couplingdevices 2 in order to enable the coupling of the scaffolding elements 4,5 at various levels. Apart from the horizontal elongate scaffoldingelements 4, 5 which form a supporting part of the scaffolding as awhole, it is possible that the coupling device 2 according to theinvention is used for the suspension of special scaffolding elements forspecial purposes, for example for anchoring lifting devices or otheraids for carrying out a specific kind of work. In such cases, suchscaffolding elements do not need to be elongated or horizontal, and canin certain cases be retained at a single upright, and be coupled to oneor more gripping parts. The scaffolding elements can, alternatively,consist of so-called lattice rails, which form rails and protection fromfalling. Several horizontal scaffolding elements 4, 5 can be coupled toone upright by means of one and the same coupling device.

The construction of the coupling device 2 will first be described withreference to FIGS. 2–5. The coupling device consists, apart from a firstcoupling part which consists of the gripping part 6, of a secondcoupling part which consists of a hook-shaped part 7 which is fixedlyattached to each end 8, or in special applications to one end of thehorizontal scaffolding elements 4. The gripping part 6 in the firstembodiment consist of a bowl-shaped unit which by means of, for examplea welding, is fixedly attached to the upright 3, in more detail to itsenveloping surface 9, which in the example shown is cylinder-shaped, butin principle can be of a shape with corners, for example a square pipe,or in principle a massive rod. In the example shown, the gripping part 6exhibits a wall 10 which extends around the enveloping surface of theupright, with a first gripping surface 11 facing inwards towards theupright which extends concentrically with the upright, i.e. with aconstant distance around the upright from the enveloping surface 9 ofthe upright. The gripping part 6 exhibits a bottom 12 whichadvantageously exhibits not shown drainage holes for water, particlesand the like. In principle, the bowl-shape can be replaced by thecylindrical wall 10 alone which is connected to the enveloping surface 9of the upright by means of stress absorbing distance elements. Thegripping part 6, regardless of its shape, forms a space 35 positionedbetween the gripping surface 11 and the enveloping surface 9 of theupright.

The hook-shaped part 7 is arranged to, when the coupling device isassembled, protrude into the space 35 of the gripping part 6 in order toengage it and be supported by it. As can best be seen from FIG. 4, thegripping surface 11 consists of a first gripping surface which isintended to interact with a second gripping surface 29 on thehook-shaped part 7, which second gripping surface faces away from theupright 3 and towards the gripping surface 11 of the gripping part 6,i.e. the first gripping surface. Although this cannot be clearly seen,the second gripping surface 29 is also advantageously curved, in moredetail it is convexly curled with essentially the same shape as thegripping surface 11 of the gripping part, by means of which surfacecontact is assured. The gripping part exhibits an upwardly facingresting surface 33 which is formed by the ring-shaped, in the exampleshown circular, edge of the wall 10. This forms a first resting area inthe coupling device, which area is arranged to interact with adownwardly facing similarly shaped resting area 34 of the hook-shapedpart 7. The resting areas 33, 34 are advantageously plane, and in theexample extend in a radial plane relative to the longitudinal axis 30 ofthe upright 3.

As can be seen from FIG. 2, the enveloping surface 9 of the upright 3forms a position limit radially inwards for the hook-shaped part 7 ininteraction with the radially inwards towards the upright facing endsurface 36 of the hook-shaped part. For reasons of tolerances, however,the hook-shaped part 7 is dimensioned so that its radial dimensions inthat part of it that protrudes downwards into the gripping part 6 arealways smaller than the radial dimension of the space 35.

However, this radial difference in the embodiments described aboveshould be less than the radial width of the downwards facing restingsurface 34 of the hook-shaped part 7 so that it cannot glide inside ofthe upwards facing resting area 33 of the gripping part 6 in a coupled,i.e. hooked but not locked position according to FIGS. 2 and 4.

In the coupling device, a locking device 37 is comprised which in FIGS.2, 4, 9, 10 is shown in a non-locking position, and in FIGS. 3, 5, 7, 8in the locking position. The locking device exhibits a first tighteningpart 38 which in the example shown is rotationally connected by means ofan axis 39, with a fixed locking body 40 which is integrated with thehook-shaped part 7, and is fixed in the scaffolding element 4. In moredetail, there is in the locking body 40 arranged a through-going cavity41 which extends from the top and downwards in whose opposite walls 42,43 the axis 39 is arranged. The axis 39 consists of an axis pin whichextends across through the cavity 41. The tightening part 38 exhibits aforwardly facing tightening surface 45 in a lower and slightlyprotruding portion 44. The direction forward in this case refers to adirection towards the upright, and backwards refers to the oppositedirection.

The tightening part 38 furthermore exhibits a rearwardly facingtightening surface 46 which faces away from the forwardly facingtightening surface, and is also arranged at the lower protruding portion44 at a distance from the joint of the tightening part, i.e. its axis39, which thus extends between the two side walls 42, 43 and, in theexample shown, also through these in a bore 47. The tightening part 38exhibits a longitudinal portion 48, which on its upper side exhibits ahole 49 through which the transverse axis 39 extends.

In the through-going cavity 41, a second tightening part 50 is arranged,and forms a locking wedge by exhibiting a downwardly facing wedge-shapeddecreasing dimension seen in the radial direction of the upright 3. Thissecond tightening part 50 exhibits an angled forward tightening surface51, which in the direction of the lower end 52 of the locking wedgegives the locking wedge its wedge-like diminishing shape.

In order to achieve a locking effect, the coupling device exhibits asupport surface for the locking wedge 50 which is formed by a rear,forwards facing tightening surface 53 arranged at the rear portion 54 ofthe locking body 55 in the through-going cavity 41.

The coupling device also exhibits a third tightening part 56, which isarranged to form a tightening point towards the upright above thegripping part 6 as well while the first tightening part 38 forms atightening point below the gripping part. In this way, the extremestiffness of the coupling device in its locked position is assured eventhough the upper tightening part 56 in principle is not entirelynecessary for the basic function. The upper tightening part 56 is anelement which is separate from the first lower tightening part 38 in theexample shown, but can alternatively form a rigid unit together with thelower tightening part in the form of a U-shaped yoke. In the exampleshown, the tightening part 56 is pivotably or flexibly connected to theaxis pin 39. The third tightening part 56 exhibits a portion whichprotrudes towards the upright 57, with a forwards facing tighteningsurface 58. Furthermore, the third tightening part 56 instead of a holefor the axis 39 exhibits a fork-shaped portion 59 with a recess 60 whichis open in the rearwards direction. In addition, the third tighteningpart exhibits a rearwardly facing tightening area 61 which is arrangedto be tightened by interaction with a forwards facing sloped tighteningsurface or wedge surface 62 of the second tightening part 50, whichbelow, for the sake of simplicity, will be referred to as the lockingwedge. The locking wedge is also mobile in the vertical directionbetween a release position shown in FIGS. 2, 4, 9 and 10, and a lockingposition shown in FIGS. 3, 5, 7 and 8. The locking wedge exhibits anelongate hole 63 through which the shaft 39 extends, and thereby thelocking wedge cannot be removed from the coupling device since its areaof movement is restricted ty the hole.

As can be seen in FIG. 6, the first and the third tightening parts areadvantageously asymmetrical in their portions in the through-going space41 in order to thereby save space. Thus, the elongate portion 48 of thefirst tightening part 38 is arranged on the one side of the lockingwedge 50, while the fork-shaped portion 59 of the third tightening part56 is arranged on the other side of the locking wedge.

According to the invention, the locking device 37 is arranged to assumea stabile release position, in more detail with the first tighteningpart 38 arranged so that it strives to assume the release position whichposition can best be seen in FIGS. 4 and 10, at the same time as itholds the locking wedge 50 in the release position. This is accomplishedby a part of the first tightening part 38 being arranged to support thelocking wedge 50 in the release position of the locking device. In moredetail, the first locking part 38 exhibits an upwardly facing supportsurface 64 which is arranged to support the locking wedge, in moredetail by the locking wedge exhibiting a downwards facing supportsurface 65, which in the example shown is formed by the downwards facingedge 52 of the locking wedge. The upwards facing supporting surface ofthe first tightening part is formed by the lower slightly protrudingpart 44 of the first tightening part. This part 44 is, also due to theabove described asymmetry, a sideways-going part, which in the sidewaysdirection protrudes from the elongate portion 48 of the first tighteningpart. In principle, the first tightening part could alternatively beU-shaped with two elongate portions and with a lower part 44 arrangedbetween them. The upwards facing support surface 64 of the firsttightening part 38 is advantageously with its shape adapted to thedownwards facing support surface 65 of the locking wedge, and is in therelease position advantageously essentially horizontal or extendsessentially in a radial plane relative to the longitudinal axis 30 ofthe upright 3. In front of the supporting surface 64, there is arrangedan upwards protruding guiding portion 66 in front of the lower end ofthe wedge said guiding portion having a guiding surface 67 adapted tothe shape of the wedge in the example shown a rounded guiding surfaceadapted to the rounded corner 68 of the wedge, see FIG. 10.

The first tightening part 38 advantageously has its centre of gravity sothat when the sideways scaffolding element is held horizontally or withthe hook-shaped part of the coupling device 7 turned upwards it strivesto assume its release position. This will become possible if thescaffolding element is at the same time rotated so that the hook-shapedcoupling part is held in a reverse position, i.e. with the hook-shapedportion facing upwards so that the locking wedge due to its own weightwill fall downwards to its release position, thus enabling the firsttightening part 38 to be pivoted to a release position. The lockingwedge will then be in a position slightly above its release position,which is made possible by the choice of the length of the elongate holeand its position so that the contact end of the hole 69 will interactwith the axis pin 39 when the support surface 65 of the locking wedge ispositioned just above the supporting surface 64 of the tightening part38.

After this, the scaffolding element 4 is rotated about its longitudinalaxis, causing the wedge to fall back into contact with the supportingsurface of the tightening part 38. Due to some friction between thesupporting surface 64 and the supporting surface 65 of the lockingwedge, it can be ensured that the tightening part 38 is retained in therelease position. Grooves or a similar locking shape can also ensurethis retainment. However, the retainment should not necessitate thelifting of the locking wedge 50 in order to move the first tighteningpart 38 to the locking position.

With the locking device in the release position, the coupling device canbe connected since the hook-formed part 7 is entered into the grippingportion 6 and rests in this by means of interaction between the grippingsurface 29 of the hook-shaped part 7 and its resting surface 34, and thecorresponding gripping surface 11 and resting surface 33 of the grippingpart and the contact surface 30 of the hook-shaped part against theenveloping surface 9 of the upright. This position is assured bygravitation giving a continuous vertical force which strives to hold thehook-shaped part in the gripping position. With the locking device inthe release position, it is in a corresponding manner simple to separatethe coupling parts by lifting the sideways scaffolding elementsvertically and to remove the hook-formed part from the gripping part.This coupling position thus holds the sideways scaffolding elements 4, 5in the scaffolding coupled.

In the coupling position, the locking device is activated by the firsttightening part 38 first being rotated to the position shown in FIGS. 3,5, 7, 8 with the forward facing tightening surface 45 on the firsttightening part being contacted to the enveloping surface 9 of theupright. From the figures it will become obvious that the firsttightening part is so shaped that it seen from the side extends aroundthe gripping part without contact with it so that exclusively theintended tightening surface 45 will come into contact with the upright.The movement of the first, i.e. the lowered tightening part 38 is doneby means by a manual activation suitably by blows using a conventionalhand tool against a backwards, downwards facing contact surface 67 of aprotruding part of the tightening part 38 protruding below the lockingbody 40. In so doing the supporting surface 64 for the locking wedge 50is removed and will thus fall into the locking position, see FIGS. 3, 5,7, 8. This will also cause the second, i.e. the upper tightening portion56 into the locking position. This is done more or less due to theweight of the wedge when the first tightening part has been moved awayso that the forwards facing tightening surface 62 of the wedge will comeinto contact with the rearwards facing tightening surface 61 of thesecond tightening part. A wedge interaction will thus be caused sincethe wedge obtains support rearwards with its rearwards facing tighteningsurface 68 in contact with the forwards facing tightening surface 53 ofthe locking body 48.

Since the various tightening surfaces are not necessarily located in thesame radial plane any torques of either the first tightening part or theother tightening part, i.e. the locking wedge is absorbed by means ofinteraction between the shaft 39 and the attachment of the first and thethird locking part in it. For a stabile wedging effect it is necessarythat the wedge angle, i.e. the slope of the tightening surfaces 51, 62cause small vertical forces upwards which are less than the frictionforces in the tightening surfaces of the wedge.

The movement of the locking device to a release position is done in ananalogous but opposite manner. The wedge 50 is struck out of the lockingposition by means of a blow from beneath with for example a hand toolagainst the supporting surface 52 possibly followed by lifting the wedgeby hand until it has reached its upper end position. In so doing thefirst tightening part 38 can swing out due to its own weight so that thesupporting surface 64 will be in a position below the supporting surface52 of the wedge following which the wedge is released downwards towardsthe supporting surface and will rest stabilly in the release position.The third tightening part 56 is also loose and the locking device is inthe release position. The hook-shaped part 7, i.e. the horizontalscaffolding element 4 can thus be lifted out of the gripping part 6.

The invention is not limited to the above described and in the drawingsshown embodiments but can be varied within the scope of the appendedclaims. For example the gripping part can alternatively consist of adisc with a number of through-going holes. It is in principle notnecessary with a third tightening part. Alternatively it is possiblethat the first and the third tightening parts are in one and the samepiece.

1. A device for coupling scaffolding elements to uprights in a scaffold,the device having both a gripping part and a hook-shaped part, thegripping part adapted for being connected to the upright and having afirst gripping surface which faces the upright and extends at a distancefrom the upright, the hook-shaped part having at least one secondgripping surface which faces away from the upright, the hook-shaped partarranged to be hooked into the gripping part and to be supported by thegripping part by interaction means between the first and the secondgripping surfaces, the device having a locking element which isswitchable between a locking position and a release position, the devicecomprising a first tightening part arranged in the hook-shaped part soas to be pivotable about a pivoting axis, a second tightening part,which is shaped as a locking wedge being pivotable about the pivotingaxis, the first tightening part and the second tightening part beingpart of the locking element.
 2. The device according to claim 1, whereinthe first tightening part includes a protruding portion having a forwardtightening surface, a rear tightening surface and a supporting surface.3. The device according to claim 1, wherein the gripping part includes afirst resting surface and the hook-shaped part includes a second restingsurface, the first resting surface and the second resting surfaceadapted to support the hook-shaped part which in the locking positionfaces downwards, the hook-shaped part being arranged to be supported byinteraction between the first and the second resting surface.
 4. Thedevice according to claim 2, wherein the second tightening part includesan elongate hole through which the pivoting axis extends.
 5. The deviceaccording to claim 4, wherein the protruding portion of the firsttightening part is arranged to support the second tightening part in therelease position.
 6. The device according to claim 1, further comprisinga third tightening part adapted to be brought against the upright bymovement of the second tightening part into the locking position.
 7. Thedevice according to claim 6, wherein the third tightening part includesa fork-shaped portion with a recess, the recess positioned about thepivot axis.
 8. A device for coupling scaffolding elements to uprights ina scaffold, the device having both a gripping part and a hook-shapedpart, the gripping part adapted for being connected to the upright andhaving a first gripping surface which faces the upright and extends at adistance from the upright, the hook-shaped part having at least onesecond gripping surface which faces away from the upright, thehook-shaped part arranged to be hooked into the gripping part and to besupported by the gripping part by interaction means between the firstand the second gripping surfaces, the device having a locking elementwhich is switchable between a locking position and a release position,the device comprising a first tightening part arranged in thehook-shaped part so as to be pivotable about a pivoting axis, a secondtightening part, which is shaped as a locking wedge being pivotableabout the pivoting axis, the first tightening part and the secondtightening part being part of the locking element; wherein the firsttightening part includes a protruding portion having a forwardtightening surface, a rear tightening surface and a supporting surface;and wherein the second tightening part includes an elongate hole throughwhich the pivoting axis extends.
 9. The device according to claim 8,wherein the protruding portion of the first tightening part is arrangedto support the second tightening part in the release position.
 10. Adevice for coupling scaffolding elements to uprights in a scaffold, thedevice having both a gripping part and a hook-shaped part, the grippingpart adapted for being connected to the upright and having a firstgripping surface which faces the upright and extends at a distance fromthe upright, the hook-shaped part having at least one second grippingsurface which faces away from the upright, the hook-shaped part arrangedto be hooked into the gripping part and to be supported by the grippingpart by interaction means between the first and the second grippingsurfaces, the device having a locking element which is switchablebetween a locking position and a release position, the device comprisinga first tightening part arranged in the hook-shaped part so as to bepivotable about a pivoting axis, a second tightening part, which isshaped as a locking wedge being pivotable about the pivoting axis, thefirst tightening part and the second tightening part being part of thelocking element; and a third tightening part adapted to be broughtagainst the upright by movement of the second tightening part into thelocking position, wherein the third tightening part includes afork-shaped portion with a recess, the recess positioned about the pivotaxis.
 11. A coupling device comprising: a first tightening part having atightening surface, said first tightening part moveable about a pivotaxis; a second tightening part moveable about said pivot axis, saidfirst tightening part and said second tightening part translatablebetween a release position and a lock position, wherein after said firsttightening part is moved about said pivot axis and into said lockposition, said second tightening part is moveable about said pivot axisinto said lock position; and a third tightening part operable betweensaid release position and said lock position, wherein said movement ofsaid second tightening part from said release position to said lockposition causes said third tightening part to move from said releaseposition to said lock position; wherein said third tightening partincludes a fork-shaped portion having a recess which is arranged aboutsaid pivot axis.
 12. The coupling device according to claim 11, whereinsaid first tightening part includes a first surface and a secondsurface, said first surface adapted to engage a scaffold when said firsttightening part is in said lock position, said second surface engagablewith said second tightening part when said first tightening part is insaid lock position.
 13. The coupling device according to claim 11,further comprising a first resting surface and a second resting surface,said first and second resting surface adapted to engage a portion of ascaffold.
 14. The coupling device according to claim 11, wherein saidsecond tightening part is wedge-shaped, further wherein said firsttightening part and second tightening part, each include a hole throughwhich said pivot axis extends.
 15. The coupling device according toclaim 11, wherein said first tightening part includes a protrudingportion arranged to underlie said second tightening part when said firstand second tightening parts are in said release position.
 16. Thecoupling device according to claim 11, wherein said pivot axis includesa pivot pin.